12 SUMMER 2015 PHI KAPPA PHI FORUM
normal, healthy individuals, height (which
reflects the activity of the GH/IGF- 1 axis)
is significantly related to the incidence of
various types of tumors, with taller individuals being at a greater risk (Batty et al., 2010).

Studies of Tom Samaras reported in numerous papers and summarized in a recent book
(Samaras 2007) uncovered many examples of
shorter people living longer than taller members of the same or related population. One
of the more striking examples of the reciprocal relationship of height and longevity was
derived from his analysis of data on professional baseball players. Information included
in The Baseball Encyclopedia: The Complete
and Definitive Record of Major League Baseball
documents that the shorter players lived, on
average, longer than the taller ones. A recent
study of American men of Japanese descent
demonstrated reduced all-cause mortality
and improved old-age survival and longevity
of shorter individuals within this cohort (He
et al., 2014). This study also revealed very
interesting associations of adult height with
genetic polymorphism of FOXO3a (a gene
regulated by IGF- 1 and with fasting insulin
levels that are influenced by GH signaling
and have been related to increased longevity
of dwarf mice).

In contrast to results obtained in mutant
mice, human dwarfism due to GH deficiency
or resistance was reported to either reduce
or have little impact on life expectancy.

However, some individuals with these syndromes reach very advanced age, including
a 100-year-old GH-deficient patient of Dr.

CONCLUSIONS:What have we learned from studiesdescribed in this article?

Our work provided evidence that mutations
of a single gene can increase both lifespan
and healthspan in a mammal, an animal very
similar to us. Studies of these and other long-lived mutants provide a unique opportunity to
discover which physiological characteristics
and mechanisms promote long life and, more
importantly, preservation of mental and physical functions into advanced age. Knowledge
that is being gained from studies of these
mechanisms is needed for developing lifestyle
nutritional and pharmacological interventions
that promote healthy aging.

Another reason to carry out studies such asthose described in this article (and continuingin our laboratory in Springfield, Illinois),is to find means of preventing some of themost dreaded diseases and dementia. Thereis a universal agreement among scientistsworking on the biology of aging that slowingthe aging process is the best and most realisticapproach to prevention of these and otherchronic diseases (Partridge 2014, Kennedy etal., 2014). I am sure that all readers will agreethat these are very important issues for eachof us, for our loved ones and for society as awhole. While a safe and effective “anti-agingpill” may still be many years away, we arealready learning how age-related diseasesand functional decline can be postponed oreven prevented by a combination of exercise,well-informed food choices and, especially,Our studies in the little mice with a surpris-ing propensity for staying healthy and livinglong are among many approaches that areused to learn what causes aging, as well ashow it can be postponed and have less impacton our lives. While much work remains, webelieve that what is already known is cause tobe optimistic about reaching these importantgoals.

Andrzej Bartke is professor of InternalMedicine and Physiology at SouthernIllinois University School of Medicine.The focus of his research is on thegenetic and hormonal control of agingin mammals. Current work is aimed atidentifying mechanisms that link reducedgrowth hormone action with delayedaging and extended longevity. For this work, he is using mutantmice that live longer than normal mice and show varioussymptoms of delayed aging, including retention of cognitivefunction and protection from age-related disease. His careerincludes work at the Jagiellonian University in Krakow, Poland;Worcester Foundation for Experimental Biology in Shrewsbury,Massachusetts; the University of Texas Health Science Center atSan Antonio; and at SIU-Carbondale. He is a past president ofthe Society for the Study of Reproduction, the American Societyof Andrology and the American Aging Association. Dr. Bartkehas published more than 750 research papers, review articlesand book chapters dealing with reproductive endocrinology,prolactin, growth hormone and aging, and has received numer-ous awards, in addition to more than 45 years of continuousNIH funding. He was the 2001-04 Phi Kappa Phi Scholar. Emailhim at abartke@siumed.edu.

While a safe and effective “anti-aging
pill” may still be many years away, we
are already learning how age-related
diseases and functional decline can be
postponed or even prevented by a combination of exercise, well-informed food
choices and, especially, by adjusting the
amount of food we eat to our physical
activity in order to maintain healthy
weight.